Improvement in propulsion of canal-boats



\ UNITED STATEs PATENT @Errea WILLIAM T. DUVALL, OF GEORGETOVVN, DISTRICT OF COLUMBIA.

IMPROVEMENT IN PROPULSlON OF CANAL-BOATS.

Specification forming part of Letters Patent N o. 116,281, datedJ une 27, 1871.

To all whom t may concern:

Be it known that I, WILLIAM T. DUVALL, of Georgetown, in the county otl Vashington and District of Columbia, have invented certain new and useful Improvements in Canal Navigation and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing, through letters of reference marked thereon, forming part of this specification, and in which- Figure l represents the bow and stern of a deeply-loaded boat, its middle portion being broken away. Fig. 2 is a section taken through the line x x on Fig. l. Fig. 3 is a similar section of an unloaded boat, both represented in a cross-section of a canal, showing the respective water-lines of the loaded and unloaded boat. Fig, 4 is a top view, in part, of the two ends of Va boat, the middle and sides being also broken away.

The same letters indicate like parts in all the gures.

In the application of steam to canal navigation by any of the various kinds of paddle-wheels, or propellers, or other meansheretofre known, waves and currents are form ed in the water which have an injurious eifect onthe banks of the canal, and have for the most part been discarded 0n that account. The ordinary means of animal traction even has a similar effect, though in less degree. The lateral or angular direction of the tow-line tending to draw the boat toward the towpath creates greater resistance against that side of the bow, and consequently a greater wave and wash from the bow displacement on that bank. This necessitates the keeping of the rudder at a greater or less angle at all times toward the opposite side, thereby creating a wave to wash the other bank, besides causing greater resistance to the traction employed.

To remedy these objections, and to apply steampower in a practical manner to canal navigation, are the-objects of my invention; which consists, mainly, in a novel application of a traction-wheel to a canal-boat and a permanent rail set in the bed of the canal. Other peculiarities of construction and operation are also embraced in my invention, which will be hereinafter described.

In the accompanying drawing, A represents the bow portion ot' a canal-boat, and B its stern portion; C, the deck of the former, and D that ofthe latter. Within these portions are constructed water-tight wells E and G, one in each, respectively, which pass vertically through the boat, and whichare tltted with guide-ways for the vertically-sliding motion of machinery and steam-cylinders connected with thetraction-wheel H and the trail-wheel I, Aall of which will be hereinafter more iully described; and in the bed of the canal are arranged two single rails, J, of wood, iron, or other suitable materialgone for the upline the other for the down-line to travel on, and which are or may be supported on piles Kdriven into the bed of the canal, or in any other suitable manner. Fitted to slide vertically within the well E is a frame, L, which supports a steamengine cylinder, a, and all its ordinary appurtenances, which operate through the pitman b and crank o to rotate the axle d, hung in suitable bearings at or near the lower portion of the frame L. This axle carries the traction-wheel H running on the rail J, and at the lower end of the frame L are provided friction-rollers e, which rotate on vertical axes at either side of the rail J to prevent the wheel H from running off the track or rail; or the wheels may be made with anges or V-shaped grooves and the side rollers in such case dispensed with. The frame L also carries another steam-cylinder, f, the piston of which is suspended by its rod g from a stationary gallows or bridge, h, spanning the well E, the purpose of which will appear in the description of operation hereinafter. The well G, nearthe stern of the boat, is provided with a similar vertically-slidin g frame, L', which carries the trail-wheel I and steam-cylinder f', the piston of which is suspended in like manner to that of the cylinder f, heretofore described. The steam-cylinders fand f are provided with openings at their upper and lower ends, suitably connected with the steamboiler, which openings are controlled by a cock or cocks, so that when the pressure is applied at the lower end of either cylinder the upper end shall be open to the atmosphere, and vice versa.

The boat, being loaded, is swung oft' until it is centrally over and parallel with the rail J in the bed of the canal. Steam is then let into the bottom of the cylinders f and f', which, operating against the stationary pistons in each, bear the frames L L and all connected with them downward until the wheels H and I ride upon the rail J, with the friction-rollers e on either side of the latter. The constant pressure of steam in the lower part of the cylinders ff acts as a steam-cushion to keep the wheels down to the track or rail with a uniform pressure, which may be increased or diminished to produce the necessary adhesion for traction. Steam then being applied to the engine a., which may be duplicated if desired to operate another crank on the other side of the wheel H, said wheel will be rotated and carry the boat forward by its adhesion to and consequent traction on the rail, while the wheel I, being borne down in like manner upon the rail, serves to guide the boat in a direct line, by which means the ordinary rudder may be dispensed with and a longer boat be admissible in the locks, thus giving more additional room in the boat than is occupied by the machinery.

It will be apparent that by the action of the steam in the cylinders] and j" the wheels H and I will be borne down to the t ack whatever depth of water the boat may draw, and will compensate for any swell in the water caused by aI passing boat, and being immediately under its center, for any rolling motion for a like cause.

By this mode of propulsion or traction there can be no disturbance of the water except what is due to the bows plowing through it; and with the additional length of the boat, by dispensing with the rudder, andthe utilizing of that portion now occupied by mules, the bows may be made much sharper without detriment to the carrying capacity, in which case the wave will be deliected at such an angle as to spend its force before striking the shore.

Vood 0r iron, but preferably the latter, may

be used for the rails; and, if found necessary to increase adhesion, a rubber tire may be used on the traction-wheel.

When itis desired to make awharf the steam is applied to the upper end of the cylinders f and f and allowed to escape from the lower part, by which the frames L and Ll are lifted into the wells E and G away from the rail; and when desired to return the frame is to be lowered by the reverse action and the boat shoved off until the rail is touched by the rollers, when, by lifting them slightly, they may be caused to span it as before.

To form a continuous connection with the rails J, a floating rail with suitable guides may be arranged within the lock, and switches at either end to guide the traction and trail-whcels onto their proper rail in entering and leaving the lock, a plan for which I have devised, which may be made the subject of another application for Lettcrs Patent if found desirable, but at present it is not believed to be necessary.

What is here claimed, and desired to be secured by Letters Patent, is-

1. The vertically-sliding frame L or Lf, in combination with the well E or Gr and traction or trail-wheels H or I, substantially as specified.

2. rlhe steam-cylinderf and its piston, in com bination with the sliding frame L and wheel H, substantially as set forth.

WM. T. DUVALL.

Witnesses:

SYDNEY E. SMITH, W. MORRIS SMITH. 

